威恩2K
种姓
密度泛函理论
分子物理学
材料科学
K-边
电子结构
吸收光谱法
物理
原子物理学
凝聚态物理
局部密度近似
量子力学
作者
Ferenc Karsai,Moritz Humer,Espen Flage−Larsen,Peter Blaha,Georg Kresse
出处
期刊:Physical review
日期:2018-12-26
卷期号:98 (23)
被引量:25
标识
DOI:10.1103/physrevb.98.235205
摘要
A detailed analysis of the theoretical x-ray absorption near-edge structures (XANES) for the boron and nitrogen $K$ edge in hexagonal boron nitride ($h$-BN) employing density-functional theory calculations is presented. The supercell core-hole method and the Bethe-Salpeter equation are used for the description of electron-hole interactions. The calculations are carried out with two different codes, the vasp and the wien2k codes, employing the projector augmented-wave and the full-potential linear augmented-plane-wave methods, respectively. We find close agreement between spectra obtained from the two codes and between calculations using the supercell core-hole method and the Bethe-Salpeter approach. All our calculations, as well as previous calculations using the ground-state structure, yield a single $2{p}_{{\ensuremath{\sigma}}^{*}}$ peak in the boron $K$-edge spectrum and hence fail to describe the experimental double-peak structure. We find that the inclusion of electron-phonon interactions is crucial to obtain the experimentally observed double-peak structure. We include these effects fully parameter free and ab initio using a one-shot sampling method and obtain excellent agreement with experiment.
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